利用探空资料验证GOME卫星臭氧数据

Validation of GOME Ozone Profiles and Tropospheric Column Ozone with Ozone Sonde over China

利用1996年3月—2003年6月部分时段拉萨、西宁、北京3个站的臭氧探空资料验证了GOME(Global Ozone Monitoring Experiment)卫星臭氧廓线及对流层臭氧柱总量。对比结果表明:在对流层中下层,拉萨和西宁两地GOME与探空的平均偏差小于5%,北京地区平均偏差小于10%;在对流层上层/平流层下层,拉萨和西宁平均偏差小于10%,北京小于20%;在平流层中上层3个站的平均偏差均小于5%。在对流层上层/平流层下层区域, GOME与臭氧探空的平均偏差在北京明显高于拉萨和西宁。3个地区对流层柱总量的平均偏差都在10%以内,表明该资料可用于研究我国对流层臭氧总量的变化规律。同时段的GOME最低层(0～2.5km)月平均臭氧浓度对比结果显示,GOME结果同地面臭氧观测值有很好的相关性,GOME臭氧浓度反映了拉萨、瓦里关、临安地面臭氧浓度的主要变化特征。

Global Ozone Monotoring Experiment （GOME） with the second Earth Remote Sencing（ERS-2）on board launched in 1995. To evaluate the performance of GOME＇s ozone data in China, ozone sonde observations at three stations in Lhasa （1998--1999）, Xining （1996）, and Beijing（2002--2003） are used to vali date ozone profiles and tropospheric column ozone retrieved from Global Ozone Monitoring Experiment （GOME）. Ozone detecting systems are electrochemical concentration cell （ECC） sonde at Lhasa and Xining and GPSO3 sonde at Beijing; GOME data are retrieved by Liu et al. A comparison dataset consists of 51 matching pairs are obtained by applying a baseline criteria （±6 h, ±3° longitude, ±1.5° latitude）. A statistical analysis of the differences between coincident Oa profiles obtained by GOME and those obtained by ozone sondes are conducted using the methodology suggested by von Clarmann. When comparing with measurements the ozone sondes vertical resolution are much better than satellite retrievals. Retrieval averaging kernels are applied to the high-resolution data so that these data are comparable. As the high-resolu tion sondes profiles do not cover the GOME retrieval altitude range, the high-resolution profile （ozone sonde only up to about 30 km） are augmented with monthly mean climatological profiles from TOMS V8. Statistical bias determination and precision validation show that in the lower and middle troposphere, the mean biases are significant within 5% at Lhasa and Xining and within 10% at Beijing. In the upper tropo- sphere and lower stratosphere, the mean biases are within 10% at Lbasa and Xining and within 20% at Beijing. In the middle and upper stratosphere, the mean biases are within 5% at all three locations. The larger bias in the troposphere and lower stratosphere at Beijing may result from a different type of ozone sonde and different time period （ozone profiles shows multiple peaks in Beijing area in the spring）. The mean biases of the tropospheric column ozone are within 10% at all three sites, which are partly caused by different estimated tropopause heights between GOME and ozone sondes. The GOME monthly mean ozone concentration at 0--2.5 km correlates well with surface ozone measurements, basically capturing the temporal variations of surface ozone at Lhasa, Waliguan, and Linan. In conclusion, from lower troposphere to upper stratosphere, GOME data used here has strong ability to reflect ozone distribution and dynamic changes in China.